﻿#region BSD 3-Clause License
/* Copyright (c) 2012, Intel Corporation
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *    
 * 3. Neither the name of Intel Corporation nor the names of its contributors may
 *    be used to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#endregion

using System;
using System.Collections.Generic;
using OpenHopla.Geometry;

namespace OpenHopla.Geometry
{
    public static class Calculator
    {
        public static  double AbsoluteValue(double value)
        {
            return (value < 0) ? -1 * value : value;
        }

        public static double Distance(OrderedPair pointA, OrderedPair pointB)
        {
            #region Parameter Validation
            const string param1Name = "pointA";
            const string param2Name = "pointB";
            if (pointA == null)
            {
                throw new ArgumentNullException(param1Name);
            }
            if (pointB == null)
            {
                throw new ArgumentNullException(param2Name);
            }
            #endregion

            double xDistance = AbsoluteValue(pointA.X - pointB.X);
            double yDistance = AbsoluteValue(pointA.Y - pointB.Y);
            return Math.Sqrt((xDistance * xDistance) + (yDistance * yDistance));
        }

        /// <remarks>
        /// Thanks to Doug Jackson for calling my attention to epsilon.
        /// John Spurgeon, 1 March 2012
        /// </remarks>
        public static bool Equals(double valueA, double valueB, double epsilon)
        {
            return AbsoluteValue(valueA - valueB) <= epsilon;
        }
    }
}
